“The address was Carlyle Square, Chelsea. I looked it up in the Directory and found she was a Mrs. Baker. Have you heard of her before?” Mrs. Neobard gave him an imploring look. “I knew her brother, the late Captain Armstrong,” the specialist said, without answering the question directly. “Please tell me everything.” Mrs. Neobard made an effort and went on. “I was disappointed, in a sense, to find that her letters weren’t worth returning to her. There was nothing in them that anyone could make use of to harm her, as far as I could see. She was simply a very foolish woman with fads. She had come to my husband out of mere curiosity, I should think, and he had played on her weakness. He had pretended that she was secretly longing to commit a murder; and the silly woman believed him. She seemed rather proud of it than otherwise. I suppose it gave her a feeling of self-importance to think of herself as a possible Mrs. Maybrick. In one of her letters she compared herself with Miladi in the ‘Three Musketeers.’” It was so exactly in keeping with his own impression of the queer little woman in Carlyle Square that Tarleton gave a nod of satisfaction. “Ah! I see you do know her. But I suppose you won’t tell me how much you know?” The physician was obliged to shake his head. “You could not trust me yourself, ma’am, if I did.” “I suppose you are right,” she admitted regretfully. “Well, I went on reading this Mrs. Baker’s letters on the chance of finding something serious in them; and at last there was. He had prompted her to think out plans for committing a murder, and she was actually sending them to him.” A gasp drew Tarleton’s attention to Sarah Neobard, who had sat hitherto listening in silence. Now she seemed roused to a sense of impending tragedy, and gazed at her mother with dilated eyes. The widow directed a swift glance at her, and withdrew it instantly. “You can understand my terrible position, Sir Frank. My eyes had been opened to my husband’s character. I don’t say that he had always been a bad man, but he had become one by now. I had the proof under my eyes that he was a criminal, and a danger to society. And here he was discussing plots of murder with a weak, silly woman who seemed to be under his thumb. Judging from her letters she was quite capable of committing a murder out of vanity, just to give herself the feeling that she was an extraordinary person.” The consultant did not credit this. But he was not there to defend Mrs. Baker, and he did not want to interrupt. “I felt that if she did commit a crime she would be doing it as my husband’s instrument, as much as if he had hypnotized her, and that I must find some way to prevent it. Then, while I was wondering how to interfere, a letter came in which she said she had a bottle of poison in her possession, a poison unknown to the medical profession, that her brother had brought with him from Sumatra. But I expect you know about that?”